Stable efficent air lubricated ship

ABSTRACT

Presented is an air lubricated ship that offers improved efficiency and stability over the prior art. Features of the preferred embodiment of the invention include: 1) a submerged bow that is generally proximal in depth to the stem, 2) a hydrofoil at the bow that not only adds stability but also allows the pressurized air layer(s) to extend further forward under the hull thereby reducing wetted area friction, 3) use of more than one air layer in series which is generally accomplished by water deflecting steps at the air layers forward portions, 4) special positioning of propulsors so that they do not interfere with the air layer(s) by aspirating pressurized air from the air layer(s), 5) optional outrigger hulls to aid to stability and to also increase useful deck area, and 6) optional configurations that allow for use of more than one air lubricated hull where such hulls are connected by structure in catamaran or other arrangements.

CROSS REFERENCE TO OTHER APPLICATIONS

[0001] This application is a continuation-in-part to U.S. applicationsSer. No. 09/388,277 filed Sep. 1, 1999 now abandoned; Ser. No.09/412,234 filed Oct. 4, 1999 now abandoned; Ser. No. 09/790,086 filedFeb. 21, 2001; and Ser. No.09/800,298 filed Mar. 5, 2001.

FIELD OF THE INVENTION

[0002] This invention relates to the field of air lubricated boat orship hulls used as means to increase the efficiencies of such hulls andto their propulsion and stabilization systems.

BACKGROUND OF THE INVENTION

[0003] The idea of placing a layer of air between the underside of aship's hull and its supporting water surface has been around for manyyears. The Russians have reported some success with this concept. FIGS.25 through 32 of this application show some of the more recent thinkingalong the line for Air Lubricated Ship designs. These are normallyreferred to in the specifications herein as the ALS.

[0004] Further, applicant has realized some commercial success with hispressurized air supported boat designs. One of these is illustrated inU.S. Pat. No. 5,839,384. That patent illustrates a boat hull where thebow of the boat operates proximal the water surface. The pressurized aircushion in a cavity built into an underside of the boat's hull depressesthe water surface going from the bow to the stem such that the stem islower than the bow. The pressure in the air cushion is essentiallyconstant over the entire area of the air cushion. Air cushioned boats ofthis general type are commonly known as Surface Effect Craft, or simplySES's, since they work on the water's surface.

[0005] There is a major difference between the ALS and the SES concepts.The forward portion of the ALS is below the water surface and creates ahole in the water. Proper location of a step in the hull and shaping ofthe aft sections of the hull of the ALS form a cavity when the ALS ismoving forward. This effect can be realized by viewing the rising of thewater behind a planing boat's hull until it reaches sea level.

[0006] An example of current thinking in ALS hull design can be seen inFIGS. 27 and 31 and 32 of this application. Blower pressurized air issupplied to the cavity formed behind the step in the hull therebycreating a pressurized air layer between portions of the bottom of theship and the supporting water surface. This, of course, reduces wettedarea friction of the hull. It is to be noted that the air cavity risesgoing from aft of the step rearward until the water surface againcontacts the hull. Efficiency gains for the ALS compared to aconventional hull are claimed to be in the twenty-percent area. Power torun the blower is very small with a rough estimate as five percent orless of propulsive power claimed.

[0007] By contrast, the SES is more of a surface-skimmer type vesselwhereby a blower-pressurized air cushion disposed below the SES's hullsupports a majority, normally about eighty percent, of vessel weight.The SES's bow is located proximal the water surface and the effect ofthe pressure in the air cushion is to depress the water level going frombow to stern. This makes for a very efficient vessel that requires onlyabout half of the propulsive power of a comparable monohull or catamaranat high speeds. However, as size and weight of the SES increase thepercentage of total power required to run the blower(s) increases ratherdramatically. Roughly speaking, blower power requirements, given as apercentage of the propulsive power requirements, range from about tenpercent for a 100 foot (30-meter) SES to more than fifty percent for a656 foot (200-meter) SES. Larger size SES's have greater proportionalblower power requirements. As a point to consider, a 100-foot (30-meter)SES would normally depress the water going from bow to stern by abouttwo feet (0.61 meter) while a 656 foot (200-meter) SES would depress thewater going from bow to stem by about 16 feet. That is eight times asmuch for the large SES.

[0008] In rough comparison: 1) The ALS gives about a twenty percentreduction in propulsive power requirements and needs about an additionalfive or less percent power for its blowers and 2) The SES generallygives about a fifty percent reduction in propulsive power requirementsbut needs from ten to over fifty percent additional power for itsblowers. The SES clearly wins the overall efficiency battle for smallersizes—say up to 350 feet (107 meters) or so. The ALS comes into primarycontention for large hulls where its need for blower power of only aboutfive or less percent of the value of its propulsive power overcomes itslower hull efficiency. A heavily loaded 656-foot (200 meter) SES wouldnormally require on the order of fifty percent of its propulsive powerto drive its blowers.

[0009] This instant application presents significant improvements to ALStechnology as applied to all type and sizes of boats and ships but isprimarily directed toward large ships. Some areas of advancement to theALS concept offered by the instant invention include: 1) Means to extendthe ALS's air cavity further forward, sometimes with multiple aircavities, and thereby further reduce hull wetted area friction, 2)Hydrofoil(s) disposed forward in the ALS's hull to both increase hullstability and to provide means to extend the air cushion further forwardin the ALS's hull, 3) Propulsion systems particularly conceived anddisposed to maximum their efficiency in ALS's, and 4) Means to stabilizethe ALS by addition of outrigger hulls. The instant invention presentsboth single and multiple ALS hull configurations.

[0010] The instant invention offers advancements over applicant'searlier inventions as well as over the prior art. These advancements arediscussed in some detail in the following sections.

SUMMARY OF THE INVENTION

[0011] The primary object of the instant invention is to offer a notableimprovement in ALS efficiency by extending the pressurized airlubrication layer(s) further forward in the ALS's hull.

[0012] A related object of the invention is that the air or gas layersbe pressurized by artificial means.

[0013] A directly related object of the invention is to provide ahydrofoil forward on the ALS that, due to its widening effect on lowerportions of the ALS's hull, allows a step that defines the forward endof the first air lubrication layer to be moved further forward.

[0014] It is a related object of the invention that the a step bepositioned at a forward portion of the air layer(s) to direct water awayfrom the ALS's hull aft of said step.

[0015] It is another related object of the invention that a lowersurface proximal to and forward of said step(s) turn downward to directwater flow downward when the improved air lubricated ship is movingforward.

[0016] It is a further related object of the invention that saidpressurized air or gas layer(s), on average, slop upward aft of step(s).

[0017] Yet another object of the invention is that the hydrofoil includeflap-like members that aid in controlling pitch and roll of said ALS.

[0018] It is a further object of the invention that an underwatersection of the improved ALS's hull, as seen in a horizontal plane takenabove the hydrofoil when the improved air lubricated ship is movingforward, is at least partially air foil shaped over its forward portionto thereby reduce drag of the hull.

[0019] It is a yet another object of the invention that a lowermostsubmerged portion of the ALS proximal a bow of the ALS be within twentypercent of the submerged depth of a lowermost portion proximal of an aftportion of said improved ALS when the ALS is moving forward in a calmsea.

[0020] It is another object of the invention that a lowermost submergedportion of the ALS proximal a bow of the ALS be within twenty-fivepercent of the submerged depth of a lowermost portion proximal of an aftportion of said improved ALS when the ALS is moving forward in a calmsea.

[0021] It is a further object of the invention that a lowermostsubmerged portion of the ALS proximal a bow of the ALS be within thirtypercent of the submerged depth of a lowermost portion proximal of an aftportion of said improved ALS when the ALS is moving forward in a calmsea.

[0022] It is a yet a further object of the invention that a lowermostsubmerged portion of the ALS proximal a bow of the ALS be withinthirty-five percent of the submerged depth of a lowermost portionproximal of an aft portion of said improved ALS when the ALS is movingforward in a calm sea.

[0023] It is still another object of the invention that a first stepforward of a first gas layer be disposed, at least in its majority, in aforward fifteen percent of a length of said improved ALS.

[0024] It is yet another object of the invention that a first stepforward of a first gas layer be disposed, at least in its majority, in aforward twenty percent of a length of said improved ALS.

[0025] It is a further object of the invention that a first step forwardof a first gas layer be disposed, at least in its majority, in a forwardtwenty-five percent of a length of said improved ALS.

[0026] It is still another object of the invention that a first stepforward of a first gas layer be disposed, at least in its majority, in aforward thirty percent of a length of said improved ALS.

[0027] It is a further object of the invention that the first gas layerbe bordered over at least a majority of its length by sidekeels.

[0028] It yet another object of the invention that it further includes asecond step in the underside of said ALS wherein said second step isdisposed, at least in its majority, proximal an aft end of said firstpressurized gas layer and wherein a second pressurized gas layer isdisposed, at least in its majority, aft of said second step.

[0029] It is a directly related object of the invention that said secondpressurized gas layer, on average, slopes upward going from forward toaft.

[0030] It is yet another object of the invention that the second gaslayer be bordered over at least a majority of its length by sidekeels.

[0031] It is a further object of the invention it may also include athird step in the underside of the ALS wherein said third step isdisposed, at least in its majority, proximal an aft end of said secondpressurized gas layer and where a third pressurized gas layer isdisposed, at least in its majority, aft of said third step.

[0032] It is a related object of the invention that the thirdpressurized gas layer, on average, slopes upward going from forward toaft.

[0033] It is a further related object of the invention that the thirdgas layer may be bordered over at least a majority of its length bysidekeels.

[0034] It is a related object of the invention that the externalsurfaces of sidekeels bordering any or all of the gas layers, as seen ina vertical transverse plane of the ALS, may be curvilinear over amajority of their lower surfaces.

[0035] It is a directly related object of the invention that theexternal surfaces of the sidekeels bordering any or all of the gaslayers, as seen in a vertical transverse plane of the ALS, may be ofcircular arc sections over a majority of their lower surfaces.

[0036] It is yet another object of the invention that sidekeelsbordering one or more gas layers may be continuous on either side of thegas layers.

[0037] It is a further object of the invention that separate artificialgas pressurization means may be used to pressurize any of the gaslayers.

[0038] It is an optional object of the invention that the sameartificial gas pressurization means may be used to pressurize two ormore gas layers.

[0039] It is a further optional object of the invention that downwardextending gas restraining seal(s) may be placed proximal an aft end ofone or more of the gas layer(s).

[0040] It is a directly related object of the invention that saiddownward extending gas restraining seal(s), as seen in verticaltransverse plane(s) of the instant invention ALS, can be angled tohorizontal over a majority of their width.

[0041] It is a further object of the invention that outrigger hulls canbe disposed either side of a main hull of said air lubricated ship.

[0042] It is a directly related object of the invention that saidoutrigger hulls can be retractable.

[0043] It is another directly related object of the invention that saidoutrigger hulls can be retractable downward such that a portion of atleast one of the outrigger hulls is disposed below one of the sidekeelsof said improved air lubricated ship.

[0044] It is yet another object of the invention that propulsors arepreferably disposed proximal an aft end of said sidekeels.

[0045] It is a related object of the invention that the propulsors arewaterjets that take in inlet water from a portion of a periphery of saidsidekeels.

[0046] It is a further related object of the invention that one or moreair fences can be disposed above and proximal to water inlets of saidwaterjets whereby said air fences restrict air from flowing downwardinto the waterjet's water inlets.

[0047] It is a further optional object of the invention that saidpropulsors can be propellers with said propellers rotating, as seen inan aft view of the improved air lubricated ship, with an upper bladerotating in an outboard direction to thereby aid in restricting gasleakage from an aft gas layer by building up a pressure front of waterover an aft end of said aft gas layer.

[0048] It is a further optional object of the instant invention thatmultiple hull ALSs to the instant invention configuration be offered.

BRIEF DESCRIPTION OF THE DRAWINGS

[0049]FIG. 1 presents a side or profile view of a preferred embodimentof the instant invention ALS. This variant has waterjet propulsors and ahydrofoil forward. Note that the bow is rather deeply submerged and at asimilar draft as the aft portions.

[0050]FIG. 2 is a bottom plan view of the ALS of FIG. 1. A first and asecond air or gas layer with each having an aft seal are shown here.

[0051]FIG. 3 is a centerline cross-sectional view, as taken through line3-3 of FIG. 2, that shows the rising, from forward to aft, first andsecond pressurized gas layers.

[0052]FIG. 4 is a similar profile view as given in FIG. 1 but in thiscase the propulsors are propellers.

[0053]FIG. 5 presents a bottom plan view of the instant invention shownin FIG. 4.

[0054]FIG. 6 gives a bow view of the instant ALS invention showing thebow hydrofoil. Note that a port trim flap is up and a starboard trimflap is down in this illustration. This orientation of the trim flapswould help prevent a roll to starboard.

[0055]FIG. 7 is a half-breadth stern view of the waterjet propelledinstant invention presented in FIGS. 1, 2, and 3.

[0056]FIG. 8 gives a half-breadth stem view of the propeller propelledinstant invention shown in FIGS 4 and 5.

[0057]FIG. 9 present a half-breadth cross-section, as taken through line9-9 of FIG. 2, that shows the first gas layer.

[0058]FIG. 10 gives a half-breath cross-section, as taken through line10-10 of FIG. 2, that shows a second gas layer. Note that the second gaslayer is higher than the first gas layer at these similar parts of theirdevelopment.

[0059]FIG. 11 is a half-breadth cross-section, as taken through line11-11 of FIG. 2, that depicts the first gas layer in way of an aft sealrestricting gas leakage from the first gas layer. Note that the aft sealis angled to horizontal over a majority of its width in this verticaltransverse plane of the instant invention ALS.

[0060]FIG. 12 is a half-breadth cross-section, as taken through line12-12 of FIG. 2, that shows a second gas layer in way of an aft sealrestricting gas leakage from said second gas layer. Note that the secondgas layer is higher than the first gas layer here.

[0061]FIG. 13 presents a similar bottom plan view as presented in FIG. 2but in this case there are three gas layers and no downward extendinggas seals. It is important to note that the instant invention canfunction with from as little as one to numerous gas layers. The showingof two and three gas layers in the figures is for illustration purposesonly.

[0062]FIG. 14 presents a centerline cross-sectional view, as takenthrough line 14-14 of FIG. 13.

[0063]FIG. 15 is a half-breadth cross-section, as taken through line15-15 of FIG. 13.

[0064]FIG. 16 is a half-breadth cross-section, as taken through line16-16 of FIG. 13.

[0065]FIG. 17 is a half-breadth cross-section, as taken through line17-17 of FIG. 13. Note the difference in the rising elevations of thegas layers in FIGS. 15, 16, and 17.

[0066]FIG. 18 presents an enlarged truncated profile view of the bow ofthe instant invention shown in FIGS. 1 and 4.

[0067]FIG. 19 presents, in its upper portion, an enlarged truncatedhalf-breadth top plan view of the instant invention presented in FIGS. 2and 5. The lower portion of FIG. 19 shows an enlarged truncatedhalf-breath bottom plan view of the instant invention presented in FIGS.2 and 5.

[0068]FIG. 20 is a cross-section, as taken through line 20-20 of FIG.19, that shows a preferred shape of the underside of the hydrofoilforward of the first gas layer. Note the water directing underwatershape just forward of the first gas layer.

[0069]FIG. 21 gives a cross-section, as taken through line 21-21 of FIG.19, that shows more details of the preferred hydrofoil shaping andlocation.

[0070]FIG. 22 is a cross-section, as taken though line 22-22 of FIG. 19,that indicates movement of an optional flap-like member at the aft endof the hydrofoil.

[0071]FIG. 23 is a half-breadth transverse cross-section, as takenthrough line 23-23 of FIG. 19, that shows a section of a hydrofoil andhow it is preferably attached to the hull.

[0072]FIG. 24 gives a half-breath transverse cross-section, as takenthrough line 24-24 of FIG. 19, that shows on of the flap-like controlmembers and its relationship to the hydrofoil and hull.

[0073]FIG. 25 presents a profile view of a prior art ALS. This shows astandard underwater propeller, a bulb bow, and upward taperingsidekeels.

[0074]FIG. 26 is a bottom plan view of the prior art ALS of FIG. 25.Note the absence of a hydrofoil forward and, also important, the factthat the first and only gas layer starts near mid-ship. The gas layermust of necessity start well aft compared to the instant invention ALSsince the bow portions are bulb shaped and/or curvilinear and then,after some distance, transition to the required flatter undersidesrequired at the forward end of the gas layer.

[0075]FIG. 27 is a cross-sectional view, as taken through line 27-27 ofFIG. 26, of the prior art ALS. Note the use of a propeller directly aftof the gas layer. This location of the propeller(s) directly aft of thegas layer results in: 1) Gas escaping from the gas layer adverselyeffecting the propeller's operation and 2) The propeller acceleratinggas out of the aft end of the gas layer thereby causing a loss of gascushion size and/or pressure.

[0076]FIG. 28 presents a transverse cross-section, as taken through line28-28 of FIG. 26, that shows the extreme curvilinear shape of the priorart ALS hull forward.

[0077]FIG. 29 shows a transverse cross-section, as taken through line29-29 of FIG. 26, that shows the still curvilinear shape of the priorart ALS hull as it goes rearward from the bow.

[0078]FIG. 30 presents a transverse cross-section, as taken through line30-30 of FIG. 26, that shows the flatter underside of the prior art ALSjust upstream of the gas layer.

[0079]FIG. 31 gives a transverse cross-section, as taken through line31-31 of FIG. 26, that shows the prior art ALS hull and gas layer shapesforward in the gas layer.

[0080]FIG. 32 presents a transverse cross-section, as taken though line32-32 of FIG. 26, that depicts the prior art ALS hull and gas layershapes proximal an aft portion of the gas layer. Note the higher levelof the gas layer here as it is rising.

[0081]FIG. 33 is a profile view of the same instant invention ALS asgiven in FIG. 1 but with the addition of stabilizing sidehulls.

[0082]FIG. 34 is a topside plan view of the outrigger hull equippedinstant invention ALS presented in FIG. 33.

[0083]FIG. 35 gives a bow view of the outrigger hull equipped instantinvention ALS presented in FIGS. 33 and 34. Note that the outrigger hullwould normally be much closer to the water surface than the main hull toreduce drag of the stabilizing outrigger hulls.

[0084]FIG. 36 presents a cross-section, as taken through line 36-36 ofFIG. 34. Note that the port side outrigger hull is retracted downwardhere for illustration purposes.

[0085]FIG. 37 gives a half-breadth bow view of the instant invention ALSas it would be docked to a pier with its port side sidehull retracteddownward.

[0086]FIG. 38 presents a bottom plan view of an instant invention ALS ina multiple-hull configuration. The outboard profile view of thismultiple hull ALS is the same as FIG. 1. In addition to the use of twoinstant invention ALS hulls in a multiple hull configuration, note thatthere is only a single gas layer shown here. This was done forillustrative purposes to show how a single gas layer would be configuredin an instant invention ALS. Note where the gas layer reattaches to thehull between the waterjet propulsors as is shown by the dashedwaterline.

[0087]FIG. 39 is a cross-sectional view, as taken through line 39-39 ofFIG. 38, that shows the single gas layer depicted here.

[0088]FIG. 40 presents a centerline cross-sectional view, as takenthrough line 40-40 of FIG. 38, that shows the cross-deck structure thatconnects the two ALS hulls in this multi-hull arrangement. Note thatwhile the single hull arrangement as earlier presented herein isnormally preferred that the instant invention ALS hulls can be arrangedin catamaran configuration, as shown here, or even in excess of two hullarrangements.

DETAILED DESCRIPTION

[0089]FIG. 1 presents a side or profile view of a preferred embodimentof the instant invention air lubricated ship (ALS) 78. Shown are ahydrofoil 50 forward, waterjet propulsor 79, waterjet inlet 77, waterjetair fence 55, starboard sidekeel 60, and waterline 64. The waterline isshown for when the ALS 78 is traveling forward in a calm sea.

[0090]FIG. 2 is a bottom plan view of the instant invention ALS 78.Shown are hydrofoil trim control flap-like members 51, 51, first air orgas layer 46, first gas layer step 71, first gas layer cavity 61, firstpressurized gas inlet 42, gas flow arrows 54, and first gas layer aftseal 48. Also shown are an optional second gas layer 47, second gaslayer step 72, second gas layer cavity 62, second pressurized gas inlet43, and second gas layer aft seal 49. Also shown is a port sidekeel 59.Note the waterlines 64 on the first and second gas layer aft seals 48,49 as these waterlines represent the reattachment of the water to theunderside of the hull at the aft end of the first and second gas layers46, 47.

[0091] It is important to realize from FIGS. 1 and 2 that the benefitsof this unique instant invention hydrofoil arrangement are severalfold.This hydrofoil arrangement provides: 1) A wide underside base so thatthe first gas layer cavity 61, and hence the first gas layer 46, can beextended far forward in the hull thereby greatly reducing wetted areafriction drag compared to prior art ALS technology, 2) Significant liftto the forward end of the hull, 3) Extreme stability in heavy seas, and4) Roll and pitch control when the optional port and starboard flap-likemembers are employed to act as ride control mechanisms.

[0092]FIG. 3 presents a centerline cross-sectional view, as takenthrough line 3-3 of FIG. 2, that shows a rising waterline 37, going fromforward to aft, under both the first and second gas layers. When movingforward, the bow or forward portion of the instant invention ALS 78 hascreated a hole in the water that the first gas layer 46 simply fills inaft of the first gas layer step 71. The first gas layer 46 ispressurized by blower 42 and the second gas layer 47, formed by secondgas layer step 72, is pressurized by second gas layer blower 43. It isimportant to note the rising waterline 37 under the gas layer(s) here.While preferable to have two or more gas layers as that approach extendsthe effective overall length of the gas layer(s) in total, it is notnecessary to have more than one gas layer to have the instant inventionALS 78 be effective. While the preferred embodiment of the instantinvention ALS 78 shows separate pressurizing blowers for each gas layerthat is not necessary. One blower can be utilized to pressurize two ormore gas layers so long as some compensation is made for the fact thateach succeeding gas layer, due to its shallower depth, normallyfunctions at a slightly lower pressure than its predecessor.

[0093]FIG. 4 presents a similar profile view of a version of the instantinvention ALS 78 as given in FIG. 1 but in this instance propelled by apropeller(s) 41.

[0094]FIG. 5 is bottom plan view of the instant invention ALS 78 havingpropeller drives 41 as was presented in FIG. 4 in a profile view.

[0095]FIG. 6 a bow view of the instant invention ALS 78 showing thehydrofoil 50, hydrofoil port trim-flap 51 and hydrofoil starboardtrim-flap 52. In this example, the port trim-flap 51 is up and thestarboard trim-flap 52 is down to correct a roll moment to starboard.Note the rising of the waterline 64 above the port trim-flap 51.

[0096]FIG. 7 gives a half-breath starboard side stern view of theinstant invention ALS 78 presented in FIGS. 1 and 2. Note the waterjetpropulsor 79 and its air fences 55. The air fences 55 help to keepsurface air from entering the waterjet's inlets.

[0097]FIG. 8 shows a half-breath port side stem view of the instantinvention ALS 78 presented in FIGS. 4 and 5. This shows a propeller 41that is mounted on an aft end of the port sidekeel 59. The direction ofrotation of the propeller 41 is shown by rotation arrow 44. This isnormally termed an outboard-rotating propeller.

[0098] Water flow arrow 45 shows some of the water coming off of thepropeller 41 is directed against the second gas layer aft seal 49 herewhich helps to reduce the amount of gas leakage from the gas layer. Theeffect of this can be realized by referring back to FIG. 5 where thewaterline 64 at the aft end of the second gas layer 47 can be seen asreattaching to the underside of the second gas layer seal 49 in aforward curving pattern because of the effect of the inboard directedpropeller wash.

[0099]FIG. 9 presents a half-breadth cross-section, as taken throughline 9-9 of FIGS. 2 and 5, that shows the first gas layer 46 proximalthe beginning of the first gas layer aft seal 61. The preferred, atleast in part, curvilinear lower portion shapes of the sidekeel 59 isshown here. These shapes can be, at least partially, of circular arcshape.

[0100]FIG. 10 is a half-breadth cross-section, as taken through line10-10 of FIGS. 2 and 5, that shows a similar position in way of thesecond gas layer aft seal 62 as was shown for the first gas layer aftseal 61 in FIG. 9. The thing to note here is the rising of the uppersurfaces and of the gas layers going from forward to aft.

[0101]FIG. 11 presents a half-breadth cross-section, as taken throughline 11-11 of FIGS. 2 and 5.

[0102]FIG. 12 presents a half-breadth cross-section, as taken throughline 12-12 of FIGS. 2 and 5. Note the rising elevation of the waterline64 going aft from FIG. 11 to FIG. 12.

[0103]FIG. 13 gives an alternative underside plan view of the inventiveALS 78 shown in profile in FIG. 1. This is the same as the undersideplan view presented in FIG. 2 except there are no gas layer aft sealsand a third gas layer 57 is shown and its associated third gas layercavity 63 is introduced. It is simply presented to show that any numberof gas layers may be used in accomplishing the instant invention ALS 78and that they can be formed with or without downward extending gas layeraft seals.

[0104] In FIG. 13, a first gas layer step 71, second gas layer step 72,and third gas layer step 73 are shown. These steps, at least in part,generally define the beginning of their following gas layers.

[0105]FIG. 14 presents a centerline cross-sectional view, as takenthrough line 14-14 of FIG. 13, that shows the shape and formation of thethree gas layers. Note that in this instance the first gas layer blower42 also supplied pressurized gas to the second gas layer. This approachsimplifies the machinery of a multiple gas layer inventive ALS 78 sinceit eliminates blower(s) and their drive engines. By having the blower 42of two separate rotating elements (not shown), it is possible to supplythe different pressures best suited for the first and second gas layers46, 47. It is also possible to use a single rotating element blower todo this by having different discharge ports on that single blower fordifferent gas layers. So, dedicated blowers can be used for each gaslayer or they can be supplied from a single blower as machineryrequirements dictate.

[0106]FIGS. 15, 16, and 17 show the rising of the gas layers going fromforward to aft.

[0107]FIG. 18 presents a truncated profile view of the instant inventionALS 78 in the bow area that shows a hydrofoil 50. Note the depth of thefirst gas layer step 71 in this preferred embodiment of the instantinvention.

[0108]FIG. 19, in its upper portion, presents a half-breadth top planview of the inventive ALS 78 given in FIG. 1. In its lower portion, itpresents a half-breadth of bottom plan view.

[0109]FIG. 20 gives a truncated centerline cross-section, as takenthrough line 20-20 of FIG. 19, in the area of the bow of the instantinvention ALS 78. The waterline under the first gas layer 46 can be seento curve downward initially here. That is caused by the optional butpreferred downward curve of the lower surface(s) forward of the firstgas layer lip 71. On average, the gas layers are angled upward goingfrom forward to aft.

[0110]FIG. 21 is a truncated cross-section, as taken through line 21-21of FIG. 19, that shows a preferred shaping of the hydrofoil at thissection.

[0111]FIG. 22 presents a cross-section, as taken though line 22-22 ofFIG. 19, that shows operation of the optional trim-flap 51. Movement ofthe trim-flap is indicated by the rotation arrow 53.

[0112]FIG. 23 gives a half-breadth cross-section, as taken through line23-23 of FIG. 19, that shows a, at least partially, curvilinear andconvex lower surface of the hydrofoil 50 in this area. The benefit ofthis is an improvement of the downstream positioned first gas layer lipdesign.

[0113]FIG. 24 is a half-breadth cross-section, as taken through line24-24 of FIG. 19, that shows a flap-like trim control member 51.

[0114]FIG. 25 presents a profile view of a prior art ALS 80. Note thebulb bow and the standard underwater propeller.

[0115]FIG. 26 is a bottom plan view of the prior art ALS 80 given inFIG. 25. Note the much abbreviated length of the first gas layer 46compared to the instant invention ALS described previously. Also notethe waterline 64 on the aft end of the first gas layer cavity 61. Thisindicates the aspirating effect of the propeller 41 on the first gaslayer 46 which has deleterious effects including: 1) A need for a morepowerful blower since the gas layer is being depleted by the aspirationof gas into the propeller and 2) A reduction in propeller efficiency dueto the gas entering the propeller blades. These deleterious effects arecaused by having the propeller, or waterjet if used, disposed directlyaft of the gas layer. Applicant's instant invention ALS avoids theseproblems by mounting the propulsors in the aft ends of the sidekeels.

[0116]FIG. 27 presents a centerline cross-sectional view of the priorart ALS 80 as taken through line 27-27 of FIG. 26. This shows the bulbor more correctly termed bulbous bow of the prior art ALS 80.

[0117]FIG. 28 presents a cross-section of the prior art ALS 80 takenproximal the bow as taken through a vertical transverse plane at line28-28 of FIG. 26.

[0118]FIG. 29 is a cross-section of the prior art ALS 80 taken aft ofsection 28-28 as taken through a vertical transverse plane at line 29-29of FIG. 26. Note that the hull shape is still rather curvilinear ornon-flat in this section.

[0119]FIG. 30 gives a cross-section, as taken through line 30-30 of FIG.26, that shows the necessary rather flat bottom surface that has beendeveloped just forward of the first gas layer cavity 61 for this priorart ALS 80.

[0120]FIGS. 31 and 32 are, respectively, cross-sections taken throughlines 31-31 and 32-32 of FIG. 26. They show the rising of the first gaslayer 46 as it goes from fore to rear in this prior art ALS 80.

[0121]FIG. 33 presents a side profile view of an instant invention ALS78 that is similar to that presented in FIG. 1 but with the addition ofoutrigger hulls-the starboard outrigger hull 67 is shown here.

[0122] A word about bow shaping for the instant invention ALS. While avertical or plumb bow is shown, any other bow shape is possible. Aninteresting bow shape that should hold promise, while not shown, is onewith part of a bulbous bow that joins with a hydrofoil proximal itslower surface. That approach gives the wider and flatter hydrofoil lowersurface combined with the low resistance characteristics of the bulbousbow. It is to be realized that the vertical or plumb bow shown hereinis, as seen in a horizontal transverse plane of the inventive ALS, atleast in part airfoil shaped over its forward portions.

[0123]FIG. 34 is a top plan view of the instant invention ALS 78 showingthe optional port and starboard outrigger hulls 66, 67. Optional hinges65 are also shown. The outrigger hulls offer: 1) Extreme stability inheavy beam seas and 2) Increased deck area compared to other ALSs.

[0124]FIG. 35 gives a bow view of the instant invention ALS 78 showingthe sidehulls extended. Note the shallow immersion of the outriggerhulls.

[0125]FIG. 36 presents a transverse section, as taken though line 36-36of FIG. 33, that shows the port sidehull 66 retracted downward with partof the sidehull below the sidekeel 59 as shown here.

[0126]FIG. 37 shows a half-breadth bow view of the outrigger hullequipped inventive ALS 78. In this case it is docked, with the inboardoutrigger hull retracted downward, close against a dock or pier 68. Thebottom 69 next to the pier 68 is also shown.

[0127]FIG. 38 presents a multi-hull, in this case in catamaranconfiguration, version of the instant invention ALS 78. Here two instantinvention ALS's are simply joined together by a connecting wetdeck 70.Each instant invention ALS hull here is the same as that presented inFIGS. 1 and 2 except there is only a first gas layer 46. This was donefor illustrative purposes as any number of gas layers may beincorporated into the instant invention ALS. It is to be realized that,although a twin hull or catamaran configuration is here used forillustration that any number of inventive ALS hulls can be used togetherin a multi-hull ALS arrangement.

[0128]FIG. 39 presents a cross-sectional view, as taken through line39-39 of FIG. 38, that shows development of the single first gas layer46 in this case.

[0129]FIG. 40 gives a cross-sectional view, as taken through line 40-40of FIG. 38, that shows the connecting deck or wetdeck 70.

[0130] Location of the propulsors in the preferred embodiment of theinstant invention is to be noted with some words here. When waterjetsare used, their preferred location is as shown in FIGS. 1, 2, 3, 7, 38,39, and 40. When propellers are used, their preferred location is asshown in FIGS. 4, 5, and 8. In each of these preferred locations thepropulsors are installed, either all or in part, in aft extensions tothe sidehulls. This locating of the propulsors provides the best air orgas free water to their rotors, little or no aspiration of gas from thegas layers, and little distortion of inlet water to the propulsors. Itis also important that the sidekeels, when they develop into theextensions just forward of the propulsors, be curvilinear in shapeexternally. The actual best shape includes circular arc shapes at leastover a majority of a lower half of the sidekeel extension(s).

[0131] While the invention has been described in connection with apreferred and several alternative embodiments, it will be understoodthat there is no intention to thereby limit the invention. On thecontrary, there is intended to be covered all alternatives,modifications and equivalents as may be included within the spirit andscope of the invention as defined by the appended claims, which are thesole definition of the invention.

What I claim is:
 1. In an improved air lubricated ship, the improvementcomprising: a hydrofoil member disposed proximal a forward portion ofsaid improved air lubricated ship, a first pressurized gas layer with aforward portion of said first pressurized gas layer disposed, at leastin its majority, aft of a first step in an underside of said improvedair lubricated ship when said improved air lubricated ship is movingforward and including a first artificial gas pressurization means tosupply pressurized gas to said first pressurized gas layer and wheresaid first pressurized gas layer, on average, slopes upward going fromforward to aft.
 2. The improved air lubricated ship of claim 1 wherein aforward portion of said first pressurized gas layer is disposed, atleast in its majority, proximal an underside of said hydrofoil when saidimproved air lubricated ship is moving forward.
 3. The improved airlubricated ship of claim 2 wherein said first step in an underside ofsaid improved air lubricated ship is at least partially disposed in anunderside of the hydrofoil.
 4. The improved air lubricated ship of claim1 wherein a lower surface proximal to and forward of said first step isturned downward to direct water flow downward when the improved airlubricated ship is moving forward.
 5. The improved air lubricated shipof claim 1 wherein said hydrofoil includes flap-like members that aid incontrolling pitch and roll of said improved air lubricated ship.
 6. Theimproved air lubricated ship of claim 1 wherein an underwater section ofthe improved air lubricated ship's hull, as seen in a horizontal planetaken above the hydrofoil when the improved air lubricated ship ismoving forward, is at least partially airfoil shaped over its forwardportions.
 7. The improved air lubricated ship of claim 1 wherein anunderwater section of the improved air lubricated ship's bow positionedabove the hydrofoil is at least in part bulbous shaped.
 8. The improvedair lubricated ship of claim 1 wherein a lowermost submerged portionproximal a bow of said improved air lubricated ship is within twentypercent of the submerged depth of a lowermost portion proximal of an aftportion of said improved air lubricated ship when the improved airlubricated ship is moving forward in a calm sea.
 9. The improved airlubricated ship of claim 1 wherein a lowermost submerged portionproximal a bow of said improved air lubricated ship is withintwenty-five percent of the submerged depth of a lowermost portionproximal of an aft portion of said improved air lubricated ship when theimproved air lubricated ship is moving forward in a calm sea.
 10. Theimproved air lubricated ship of claim 1 wherein a lowermost submergedportion proximal a bow of said improved air lubricated ship is withinthirty percent of the submerged depth of a lowermost portion proximal ofan aft portion of said improved air lubricated ship when the improvedair lubricated ship is moving forward in a calm sea.
 11. The improvedair lubricated ship of claim 1 wherein said first step is disposed, atleast in its majority, in a forward fifteen percent of a length of saidimproved air lubricated ship.
 12. The improved air lubricated ship ofclaim 1 wherein said first step is disposed, at least in its majority,in a forward twenty percent of a length of said improved air lubricatedship.
 13. The improved air lubricated ship of claim 1 wherein said firststep is disposed, at least in its majority, in a forward twenty-fivepercent of a length of said improved air lubricated ship.
 14. Theimproved air lubricated ship of claim 1 wherein said first step isdisposed, at least in its majority, in a forward thirty percent of alength of said improved air lubricated ship.
 15. The improved airlubricated ship of claim 1 wherein said first gas layer is bordered overat least a majority of its length by sidekeels.
 16. The improved airlubricated ship of claim 1 which further comprises a second step in theunderside of said air lubricated ship wherein said second step isdisposed, at least in its majority, proximal an aft end of said firstpressurized gas layer and wherein a second pressurized gas layer isdisposed, at least in its majority, aft of said second step and wheresaid second pressurized gas layer, on average, slopes upward going fromforward to aft and is bordered over at least a majority of its length bysaid sidekeels.
 17. The improved air lubricated ship of claim 16 whichfurther comprises a third step in the underside of the air lubricatedship wherein said third step is disposed, at least in its majority,proximal an aft end of said second pressurized gas layer and where athird pressurized gas layer is disposed, at least in its majority, aftof said third step and wherein said third pressurized gas layer, onaverage, slopes upward going from forward to aft and is bordered over atleast a majority of its length by said sidekeels.
 18. The improved airlubricated ship of claim 16 wherein the second gas layer receivespressurized gas from the first artificial gas pressurization means. 19.The improved air lubricated ship of claim 16 wherein the second gaslayer receives pressurized gas from a second artificial gaspressurization means.
 20. The improved air lubricated ship of claim 17wherein the third gas layer receives pressurized gas from an artificialgas pressurization means.
 21. The improved air lubricated ship of claim1 which further comprises a first downward extending gas restrainingseal positioned proximal an aft end of said first gas layer.
 22. Theimproved air lubricated ship of claim 21 wherein said first downwardextending gas restraining seal, as seen in a vertical transverse planeof the improved air lubricated ship, is angled to horizontal over amajority of its width.
 23. The improved air lubricated ship of claim 16which further comprises a second downward extending gas restraining sealpositioned proximal an aft end of said second gas layer.
 24. Theimproved air lubricated ship of claim 23 wherein said second downwardextending gas restraining seal, as seen in a vertical transverse planeof the improved air lubricated ship, is angled to horizontal over amajority of its width.
 25. The improved air lubricated ship of claim 17which further comprises a third downward extending gas restraining sealpositioned proximal an aft end of said third gas layer.
 26. The improvedair lubricated ship of claim 25 wherein said third downward extendinggas restraining seal, as seen in a vertical transverse plane of theimproved air lubricated ship, is angled to horizontal over a majority ofits width.
 27. The improved air lubricated ship of claim 1 which furthercomprises outrigger hulls disposed either side of a main hull of saidair lubricated ship.
 28. The improved air lubricated ship of claim 27wherein said outrigger hulls are retractable.
 29. The improved airlubricated ship of claim 28 wherein said outrigger hulls are retractabledownward such that a portion of at least one of the outrigger hulls isdisposed below one of the sidekeels of said improved air lubricatedship.
 30. The improved air lubricated ship of claim 1 wherein propulsorsare disposed proximal an aft end of said sidekeels.
 31. The improved airlubricated ship of claim 30 wherein said propulsors are waterjets thattake in inlet water from a portion of a periphery of said sidekeels. 32.The improved air lubricated ship of claim 31 which further comprises oneor more air fences disposed above and proximal to water inlets of saidwaterjets whereby said air fences restrict air from flowing downwardinto the waterjet's water inlets.
 33. The improved air lubricated shipof claim 30 wherein said propulsors are propellers with said propellersrotating, as seen in an aft view of the improved air lubricated ship,with an upper blade rotating in an outboard direction to thereby aid inrestricting gas leakage from an aft gas layer by building up a pressurefront of water over an aft end of said aft gas layer.
 34. The improvedair lubricated ship of claim 30 wherein an external portion of thesidekeels proximal the propulsors is, at least in their majority,curvilinear.
 35. The improved air lubricated ship of claim 1 whereinthere are multiple air lubricated hulls in mechanical communication bymeans of a connecting structure.
 36. In an improved air lubricated shipincluding a first pressurized gas layer disposed, at least in itsmajority, aft of a first step in an underside of said air lubricatedship when said air lubricated ship is moving forward and including afirst artificial gas pressurization means to supply pressurized gas tosaid first pressurized gas layer and where said first pressurized gaslayer, on average, slopes upward going from forward to aft and isbordered over at least a majority of its length by sidekeels, theimprovement comprising: a second step in the underside of the airlubricated ship wherein said second step is disposed, at least in itsmajority, proximal an aft end of said first pressurized gas layer andwherein a second pressurized gas layer is disposed, at least in itsmajority, aft of said second step and where said second pressurized gaslayer, on average, slopes upward going from forward to aft and isbordered over at least a majority of its length said sidekeels.
 37. Theimproved air lubricated ship of claim 36 which further comprises a thirdstep in the underside of the air lubricated ship wherein said third stepis disposed, at least in its majority, proximal an aft end of saidsecond pressurized gas layer and wherein a third pressurized gas layeris disposed, at least in its majority, aft of said third step and wheresaid third pressurized gas layer, on average, slopes upward going fromforward to aft and is bordered over at least a majority of its length bysaid sidekeels.
 38. The improved air lubricated ship of claim 36 whereina lower surface proximal to and forward of said first step is turneddownward to direct water flow downward when the improved air lubricatedship is moving forward.
 39. The improved air lubricated ship of claim 36wherein the second gas layer receives pressurized gas from the firstartificial gas pressurization means.
 40. The improved air lubricatedship of claim 36 wherein the second gas layer received pressurized gasfrom a second artificial gas pressurization means.
 41. The improved airlubricated ship of claim 37 wherein the third gas layer receivespressurized gas from an artificial gas pressurization means.
 42. Theimproved air lubricated ship of claim 36 which further comprises ahydrofoil member disposed proximal a forward portion of said airlubricated ship.
 43. The improved air lubricated ship of claim 42wherein a forward portion of said first pressurized gas layer isdisposed, at least in its majority, proximal an underside of saidhydrofoil when said improved air lubricated ship is moving forward. 44.The improved air lubricated ship of claim 42 wherein an underwatersection of the improved air lubricated ship's hull, as seen in ahorizontal plane taken above the hydrofoil when the improved airlubricated ship is moving forward, is at least partially airfoil shapedover its forward portions.
 45. The improved air lubricated ship of claim42 wherein an underwater section of the improved air lubricated ship'sbow positioned above the hydrofoil is at least in part bulbous shaped.46. The improved air lubricated ship of claim 42 wherein said hydrofoilincludes flap-like members that aid in controlling pitch and roll ofsaid air lubricated ship.
 47. The improved air lubricated ship of claim36 which further comprises a first downward extending gas restrainingseal positioned proximal an aft end of said first gas layer.
 48. Theimproved air lubricated ship of claim 47 wherein said first downwardextending gas restraining seal, as seen in a vertical transverse planeof the improved air lubricated ship, is angled to horizontal over amajority of its width.
 49. The improved air lubricated ship of claim 36which further comprises a second downward extending gas restraining sealpositioned proximal an aft end of said second gas layer.
 50. Theimproved air lubricated ship of claim 49 wherein said second downwardextending gas restraining seal, as seen in a vertical transverse planeof the improved air lubricated ship, is angled to horizontal over amajority of its width.
 51. The improved air lubricated ship of claim 37which further comprises a third downward extending gas restraining sealpositioned proximal an aft end of said third gas layer.
 52. The improvedair lubricated ship of claim 51 wherein said third downward extendinggas restraining seal, as seen in a vertical transverse plane of theimproved air lubricated ship, is angled to horizontal over a majority ofits width.
 53. The improved air lubricated ship of claim 36 wherein alowermost submerged portion proximal a bow of said improved airlubricated ship is within twenty percent of the submerged depth of alowermost portion proximal of an aft portion of said improved airlubricated ship when the improved air lubricated ship is moving forwardin a calm sea.
 54. The improved air lubricated ship of claim 36 whereina lowermost submerged portion proximal a bow of said improved airlubricated ship is within twenty-five percent of the submerged depth ofa lowermost portion proximal of an aft portion of said improved airlubricated ship when the improved air lubricated ship is moving forwardin a calm sea.
 55. The improved air lubricated ship of claim 36 whereina lowermost submerged portion proximal a bow of said improved airlubricated ship is within thirty percent of the submerged depth of alowermost portion proximal of an aft portion of said improved airlubricated ship when the improved air lubricated ship is moving forwardin a calm sea.
 56. The improved air lubricated ship of claim 36 whereinsaid first step is disposed, at least in its majority, in a forwardfifteen percent of a length of said improved air lubricated ship. 57.The improved air lubricated ship of claim 36 wherein said first step isdisposed, at least in its majority, in a forward twenty percent of alength of said improved air lubricated ship.
 58. The improved airlubricated ship of claim 36 wherein said first step is disposed, atleast in its majority, in a forward twenty-five percent of a length ofsaid improved air lubricated ship.
 59. The improved air lubricated shipof claim 36 wherein said first step is disposed, at least in itsmajority, in a forward thirty percent of a length of said improved airlubricated ship.
 60. The improved air lubricated ship of claim 36 whichfurther comprises outrigger hulls disposed either side of a main hull ofsaid air lubricated ship.
 61. The improved air lubricated ship of claim60 wherein said outrigger hulls are retractable.
 62. The improved airlubricated ship of claim 61 wherein said outrigger hulls are retractabledownward such that a portion of at least one of the outrigger hulls isdisposed below one of the sidekeels of said improved air lubricatedship.
 63. The improved air lubricated ship of claim 36 whereinpropulsors are disposed proximal an aft end of said sidekeels.
 64. Theimproved air lubricated ship of claim 63 wherein said propulsors arewaterjets that take in inlet water from a portion of a periphery of saidsidekeels.
 65. The improved air lubricated ship of claim 64 whichfurther comprises one or more air fences disposed above and proximal towater inlets of said waterjets whereby said air fences restrict air fromflowing downward into the waterjet's water inlets.
 66. The improved airlubricated ship of claim 63 wherein said propulsors are propellers withsaid propellers rotating, as seen in an aft view of the improved airlubricated ship, with an upper blade rotating in an outboard directionto thereby aid in restricting gas leakage from an aft gas layer bybuilding up a pressure front of water over an aft end of said aft gaslayer.
 67. The improved air lubricated ship of claim 63 wherein anexternal portion of the sidekeels proximal the propulsors is, at leastin their majority, curvilinear.
 68. The improved air lubricated ship ofclaim 36 wherein there are multiple air lubricated hulls in mechanicalcommunication by means of a connecting structure.
 69. In an improved airlubricated ship, the improvement comprising: a hydrofoil member disposedproximal a forward portion of said improved air lubricated ship, a firstpressurized gas layer with a forward portion of said first pressurizedgas layer disposed, at least in part, in an underside of said hydrofoilwhen said improved air lubricated ship is moving forward and including afirst artificial gas pressurization means to supply pressurized gas tosaid first pressurized gas layer.
 70. The improved air lubricated shipof claim 69 wherein said first pressurized gas layer, on average, slopesupward going from forward to aft.
 71. The improved air lubricated shipof claim 69 which further includes a first step proximal a forward endof said first pressurized gas layer.
 72. The improved air lubricatedship of claim 71 wherein said first step is at least partially disposedin an underside of the hydrofoil.
 73. The improved air lubricated shipof claim 69 which further comprises a second pressurized gas layerdisposed, at least in its majority, aft of a second step.
 74. Theimproved air lubricated ship of claim 73 which further comprises a thirdpressurized gas layer disposed, at least in its majority, aft of a thirdstep.